This feature allows to enable audit of actions for app circles.

The motivation for this change is documented in forum.

It's a feature configurable. It doesn't change current behaviour, only adds audit of actions. It can be desirable feature for customers that want to have an wide control of user actions.

The following actions are audited:

1. user X creates circle Z;
2. user X removes circle Z;
3. user X changes name of circle Z to circle W;
4. member X is added to circle Y by user Z;
5. member X is removed from circle Y by user Z;
6. user X shares fiel/folder with circle Y;
   7a. user X, that created circle Y, unshares file/folder with circle Y;
   7b. user Z,that is member of circle Y, unshares file/folder with circle Y.